Method of making brushes



Patented @ct 3% W23.

unites stares @ATENT FFHQEO WILLIAIZL' 1E. GRAVE, OF NORTHAMPTON, MASSAQHUSETTS, ASSIGNOR Z330 FANNIE E. 1409K, ELDON MACLEOD, WILLIAM CORDES, AND GEORGE E. BURN, TRUSTEES, 10)- ING BUSINESS AS FLORENCE MFACTURING COMPANY.

METHOD OF MAKING- BRUSHES.

E70 Drawing.

To aZZwhom it may concern:

Be it known that l, WILLIAM F. GRAUL, a citizen of the United States, residin at Northampton, county of Hampshire, tate of Massachusetts, have invented a certain new and useful Improvement in Methods of Making" Brushes, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has to do with a new and improved method of making brushes and particularly such toilet and tooth brushes as have a celluloid or pyrozylin baclr in which are set tults of bristles. Difficulty has been experienced in past in the manufacture of brushes or this nature and particularly those in which the tufts of bristles are secured in place by staples because the bristles forming the tufts ire quently worlr loose or crack under the staple and finally break and work out oi the hole. This diliiculty is caused in part by the strain to which the bristle is subjected as it is being inserted, it being bent sharply upon itself, and in part to the fact that the hole in which the cult is setis necessarily slightly larger than the diameter of the tuft of bristles, so that the bristle can work baclr and forth slightly. Although this movement is minute, it eventually causes the bristle to come out. Attempts have been made to compress the celluloid composing the brush back about the tufts of bristles, but such attempts have not been successful for reasons which need not be explained in detail herein.

l have discovered that it the celluloid sur' rounding the hole in which the tuft oil bristles is set is treated with some solvent of celluloid after the tuft of bristles has been set and then the solvent is allowed to dry, the celluloid will be contracted or shrunk about the butt oi bristles and the bristles will be held in place so firmly that they cannot work out of the hole. In practising iny improved process, no adhesive such as collodion is employed as has been heretolore suggested, and therefore the bristles employed in my novel process may be said to be in their natural state, even thouuh they may be temporarily moistened with the Application filed March 3, 1919. Serial Ito. 280,504.

solvent with which the walls of the holes are treated either directly by application to the walls of the holes or indirectly by application to the bristles and thence to the Walls of the holes. My improved method is applicable not only to brushes the tufts of bristles of which are held in by anchors but also to drawn brushes.

Suitable liquids for this purpose are amyl or ethyl acetate, acetone, or a mixture of some of them with certain nomsolvent liquids as will be well understood by those skilled in the manipulation of celluloid.

Various methods for treating, re celluloid about the holes, all of said methods being within the scope of my present invention, are practical. For instanc a v ute drop of solvent may be placed in ole just etore the of bristles is set, or folded of each tuft of bristles be treated with the solvent just b e it is set. I I find, however, that the w can be more effectively peri 'nied in snot r manner. The holes are drilled and tsof bristles are all set in brush in the well known manor, as nstance, by an automatic drilling .5 setting the brush may be by Th ealter, the ends of the bristles composi g brush are dipped in shallow dish contr' ing the solvent and held there lor enough to permit the solvent to bristle by capillary attraction arid reach the brush back. This occurs alniost instan taneously. The portion or the br stl is wet with the solvent is of slightly color from the dry bristle, and alter the tufts oi bristles have been dipped in the solvent, the change in color will be; seen to character of the brush. Brushes which have thus been treated very seldom shed any bristles.

What I claim is:

1. The method of making brushes Which consists in setting tufts of bristles in their natural state in holes formed in celluloid brush backs and by the application of a solvent of celluloid, causing the original material of the brush back about the several tufts to engage the bristles and secure the same in place.

2. The method of making brushes which consists in setting tufts of bristles in their natural state in holes formed in celluloid brush backs and by the application of a solvent containing amyl acetate causing the original material of the brush back about the several tufts to engage the bristles and secure the same in place.

3. The process of making a brush having a celluloid back and tufts of bristles set amaiee therein which consists in applying a solvent of celluloid to a free portion of the bristles and allowing the said solvent to reach the brush back by capillary attraction.

4. The process of making a brush Which consists in setting the tufts of bristles in their natural state in a celluloid brush back and then applying a solvent of celluloid to the portion of the brush back immediately about the holes in which the bristles are set to cause the brush back about the tufts of bristles to contract.

5. The process of making a brush which consists in setting tufts of bristles in a celluloid back, then dipping the free ends of the bristles in a celluloid solvent, and then allowin the brush to dry .While suspended Wit 1 the free ends of the bristles 40 down.

In testimony whereof I afiix my signature.

WILLIAM F. GRAUL. 

